Eclipse Plugin Development - No schema found for the org.eclipse.wst.server.core.serverTypes extensi

I am trying to create a new server type plugin programmatically and after re-search I found that I need to use org.eclipse.wst.server.core.serverTypes extension point, but when I try to add above extension point in eclipse juno sdk, I am getting "No schema found..." error . Can anyone please guide me why I am getting above error? Am I missing any required dependencies here?

FYI, I have added org.eclipse.wst.server.core and org.eclipse.wst.server.ui as an dependencies but still no luck and Googling leads to resources for other extension points but not for this. Any guidance is highly appreciated.